/Engine/Source/Runtime/Engine/Public/MaterialShared.h
const [FMemoryImageString](API\Runtime\Core\Serialization\FMemoryImageString) * GetShaderSource ( const [FVertexFactoryType](API\Runtime\RenderCore\FVertexFactoryType) * VertexFactoryType, const [FShaderType](API\Runtime\RenderCore\FShaderType) * ShaderType, int32 PermutationId ) const